Why are my Remy hair extensions dry and frizzy?

I have recently bought Remy hair extensions which are supposed to be best. I wanted to have extensions because my hair is not very healthy and it grows very slowly. I have had these hair extensions for two weeks or so but they already look and feel like straw which is my own hair looked and felt. Why are my Remy hair extensions dry and frizzy? What would be the reason behind it? What can I do about it? Can anybody help? I would really appreciate your feedback pertaining to my query at the earliest. Thanks.